If 500 gm of salt solution has 30% salt in it, how much salt must be added to make the concentration of salt 50% in the solution?
Answer: A
Amount of water in solution = 100 % - 30 % = 70 % of total
Amount of water = 70 % × 500 = 350 gm
Amount of water remains same for both the solutions. Therefore, let amount of new solution be x gm.
x = 350 × (100/ 50)
x = 700
Salt added = (700 – 500) = 200 gm
Alternate solution:
Quantity of sugar to be added :
= [Solution (Required % value – Present % value)] / (100 – Required % value)
= [500 (50 – 30)] / 100 – 50
= (500 × 20) / 50
= 200 gm